Re: OT question sorry but i need salution fast ....
On Thu, 13 Jun 2002 00:47:17 -0400, Anthony DeRobertis wrote: On Tuesday, June 11, 2002, at 02:14 , faisal gillani wrote: well i have 2 ethernet networks running which i want to connect but the distance between them is above 400 meters .. so this is way beyond the normal lan hardware .. snip The only thing that will stop you[1] is if the signal is not strong enough on the other end, or the noise has won. Amps might help, as would lower gauge wire. I'd be interested in hearing how how far you can get away with cat5. This strikes me as an RF transmission line problem. Twisted pairs (cat5) are a reasonably low loss transmission line at audio and low rf. At 1 gHz they become very lossy. (I know, we're not talking more than 100 mb/s, but these are square waves which have high value odd harmonic components---3rd, 5th, 7th, 9th, and etc overtones.) Since these harmonics are attenuated more than the fundamental (a transmission line is a low pass filter), the effect is to slow the rise and fall times of the wave form. This may cause the detector to mis-read the signal. Unless active devices are used to regenerate the wave form within acceptable loss-distance, _very_ high quality (read air dielectric coax (hardline), or balanced twin lines) transmission lines are necessary. snip [1] Before someone starts yelling collision domain, remember I said 'full duplex'. There should be no collisions, and hence no problematic late collisions. Thus, dual transmission lines, native to cat5. -- gt Everything here could be wrong--Messiah's Handbook--Bach -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
On Tuesday, June 11, 2002, at 02:14 , faisal gillani wrote: well i have 2 ethernet networks running which i want to connect but the distance between them is above 400 meters .. so this is way beyond the normal lan hardware .. First off, you might be able to get away with it. Make sure the link is running in full duplex --- between two routers, for example --- if you want any chance. The only thing that will stop you[1] is if the signal is not strong enough on the other end, or the noise has won. Amps might help, as would lower gauge wire. I'd be interested in hearing how how far you can get away with cat5. The second option --- and this one will work --- is media converters. They are about $100 each off ebay. They will let you run 10km or so of fiber, far more than 400m. But this would require the use of fiber. Fiber has the advantage of not conducting as well. [1] Before someone starts yelling collision domain, remember I said 'full duplex'. There should be no collisions, and hence no problematic late collisions. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
OT question sorry but i need salution fast ....
well sorry fro this but i couldent find any other place to ask this question i need the salution very badly this will gratly benift me well i have 2 ethernet networks running which i want to connect but the distance between them is above 400 meters .. so this is way beyond the normal lan hardware .. i am here in pakistan where no such high bandwith devices or support exisit .. i was thinking about that thicknet cable but dont know what hardware to get for this .. also are there any wireless hardwares for this senario ? thanks you very much for reading = *º¤., ¸¸,.¤º*¨¨¨*¤ Allah-hu-Akber*º¤., ¸¸,.¤º*¨¨*¤ __ Do You Yahoo!? Yahoo! - Official partner of 2002 FIFA World Cup http://fifaworldcup.yahoo.com -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
At 2002-06-11T18:14:24Z, faisal gillani [EMAIL PROTECTED] writes: well sorry fro this but i couldent find any other place to ask this question i need the salution very badly this will gratly benift me well i have 2 ethernet networks running which i want to connect but the distance between them is above 400 meters .. so this is way beyond the normal lan hardware .. I'm not saying that this is an ideal solution, but could you install a cheap 4-port switch (not hub!) every 100 meters? Since switches generates signals themselves, rather than just passing the original electrical signal, that might extend your range sufficiently. Anyone care to tell me if or why this is a bad idea? -- Kirk Strauser The Strauser Group - http://www.strausergroup.com/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
Kirk Strauser wrote: At 2002-06-11T18:14:24Z, faisal gillani [EMAIL PROTECTED] writes: well sorry fro this but i couldent find any other place to ask this question i need the salution very badly this will gratly benift me well i have 2 ethernet networks running which i want to connect but the distance between them is above 400 meters .. so this is way beyond the normal lan hardware .. I'm not saying that this is an ideal solution, but could you install a cheap 4-port switch (not hub!) every 100 meters? Since switches generates signals themselves, rather than just passing the original electrical signal, that might extend your range sufficiently. Anyone care to tell me if or why this is a bad idea? You are correct about switches regenerating the signal, but why not just connect the two networks with fiber. Fiber will cost the same (or possibly less) to run between the two locations, will eliminate the need for multiple switches, and as a bonus will eliminate issues like grounding concerns (I'm guessing the two locations are in seperate buildings, if so, grounding and lightening protection become a hassle with copper). Toss a media converter on each end (or a fiber card for a router or switch), and you're set. As a further bonus, you'll easily be able to upgrade to higher speed networking between the ethernets just by replacing the equipment on each end. --Rich _ Rich Puhek ETN Systems Inc. _ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
I'm not saying that this is an ideal solution, but could you install a cheap 4-port switch (not hub!) every 100 meters? Anyone care to tell me if or why this is a bad idea? A device is a device, right ?? Whether it's a network card, hub, or switch, keep the distance between them under 100 meters. Sounds logical ;-) Hall -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
No, I don't think you're right. Hubs are effectively passive, so they don't count as a termination point (IIRC). Switches -- or, for that matter, repeaters -- do, since they are active devices. ap -- Andrew J Perrin - http://www.unc.edu/~aperrin Assistant Professor of Sociology, U of North Carolina, Chapel Hill [EMAIL PROTECTED] * andrew_perrin (at) unc.edu On Tue, 11 Jun 2002, Hall Stevenson wrote: I'm not saying that this is an ideal solution, but could you install a cheap 4-port switch (not hub!) every 100 meters? Anyone care to tell me if or why this is a bad idea? A device is a device, right ?? Whether it's a network card, hub, or switch, keep the distance between them under 100 meters. Sounds logical ;-) Hall -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
At 2002-06-11T18:41:56Z, Rich Puhek [EMAIL PROTECTED] writes: You are correct about switches regenerating the signal, but why not just connect the two networks with fiber. See also: his mention of living in a technologically depressed area. Switches *may* be easier to come by than fiber, especially if they've already invested in a CAT-5 infrastructure (and therefore have the tools, cable, crimp ends, and training to do it themselves). -- Kirk Strauser The Strauser Group - http://www.strausergroup.com/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
Hall Stevenson wrote: I'm not saying that this is an ideal solution, but could you install a cheap 4-port switch (not hub!) every 100 meters? Anyone care to tell me if or why this is a bad idea? A device is a device, right ?? Whether it's a network card, hub, or switch, keep the distance between them under 100 meters. Sounds logical ;-) Wrong... The following: (PC#1)-HUB-HUB--(PC#2) is NOT the same as: (PC#1)-switch--switch-(PC#2) The problem is, a hub just electrically connects the signal (handling crossover, etc). A Switch will completely regenerate the signal on the other port(s). The overall length applies to each segment. The top diagram is one segment, which can have an *overall* length of 100 meters, not 400 meters as your analysis might imply. The bottom diagram can have 100m between the first PC and the first switch, 100m between the two switches, and 100m between the 2nd switch and the 2nd PC (assuming 10 base-T Ethernet). The issue, IIRC, has to do with the minimum size of an Ethernet frame, the speed at which the frame propagates down the physical wire, and the need for all devices to be properly able to sense a collision. Basicly, if the overall length of the network is too long, PC#1 could begin transmitting a frame while listening for a collision. PC#2, if far enough away, could start transmitting a frame at nearly the same time, also listening for a collision. If the network is long enough to introduce enough delay that the start of the frame transmitted by PC#1 did not reach PC#2 before PC#2 was done transmitting (and if the frame from PC#2 did not reach PC#1 before PC#1 was done transmitting) neither side would detect a collision. The result would be a corrupted packet, which would hopefully be handled at a higher layer. I'm a test engineer by trade, not a communications engineer, so my explanation may be a bit off. Anyone have a copy of IEEE 802.3 laying around? I assume that deals with this problem in more detail. --Rich _ Rich Puhek ETN Systems Inc. _ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: OT question sorry but i need salution fast ....
The issue, IIRC, has to do with the minimum size of an Ethernet frame, the speed at which the frame propagates down the physical wire, and the need for all devices to be properly able to sense a collision. [...] Exactly. A switch divides the collision domain. The max edge-to-edge latency within a collision domain is strictly limited for the reasons you describe. All ports on a hub are still in the same collision domain, so adding a hub doesn't let you start over when you're adding up max lengths. -- Grant Edwards grante Yow! .. does your DRESSING at ROOM have enough ASPARAGUS? visi.com -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
